Package org.minidns.dnslabel

Class LdhLabel

java.lang.Object

org.minidns.util.SafeCharSequence

org.minidns.dnslabel.DnsLabel

org.minidns.dnslabel.LdhLabel

All Implemented Interfaces:

CharSequence, Comparable<DnsLabel>

Direct Known Subclasses:

NonReservedLdhLabel, ReservedLdhLabel

public abstract class LdhLabel
extends DnsLabel

A LDH (Letters, Digits, Hyphen) label, which is the classical label form.

Note that it is a common misconception that LDH labels can not start with a digit. The origin of this misconception is likely that RFC 1034 § 3.5 specified

They [i.e, DNS labels] must start with a letter, end with a letter or digit, and have as interior characters only letters, digits, and hyphen.

. However, this was relaxed in RFC 1123 § 2.1

One aspect of host name syntax is hereby changed: the restriction on the first character is relaxed to allow either a letter or a digit.

and later summarized in RFC 3696 § 2:

If the hyphen is used, it is not permitted to appear at either the beginning or end of a label.

Furthermore RFC 5890 § 2.3.1 only mentions the requirement that hyphen must not be the first or last character of a LDH label.

See Also:

• RFC 5890 § 2.3.1. LDH Label

Nested Class Summary

Nested classes/interfaces inherited from class org.minidns.dnslabel.DnsLabel

DnsLabel.LabelToLongException

Field Summary

Fields inherited from class org.minidns.dnslabel.DnsLabel

label, MAX_LABEL_LENGTH_IN_OCTETS, VALIDATE, WILDCARD_LABEL

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	LdhLabel(String label)

Method Summary

Modifier and Type	Method	Description
protected static LdhLabel	fromInternal(String label)
static boolean	isLdhLabel(String label)

Methods inherited from class org.minidns.dnslabel.DnsLabel

asLowercaseVariant, compareTo, consistsOnlyOfLettersDigitsAndHypen, consistsOnlyOfLettersDigitsHypenAndUnderscore, equals, from, from, getInternationalizedRepresentation, getInternationalizedRepresentationInternal, getLabelType, getRawLabel, hashCode, isIdnAcePrefixed, toSafeRepesentation, toString, writeToBoas

Methods inherited from class org.minidns.util.SafeCharSequence

charAt, length, subSequence, toSafeString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.lang.CharSequence

chars, codePoints

Constructor Details

LdhLabel

protected LdhLabel(String label)

Method Details

isLdhLabel

public static boolean isLdhLabel(String label)

fromInternal

protected static LdhLabel fromInternal(String label)